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At least 955 records · Page 53Linked to original sources
USGS2009

Integrated analysis of flow, temperature, and specific-conductance logs and depth-dependent water-quality samples from three deep wells in a fractured-sandstone aquifer, Ventura County, California

Analysis of flow, temperature, and specific-conductance logs and depth-dependent water-quality samples collected under ambient and pumped conditions provided a preliminary delineation of flow zones and water quality in three deep abandoned water-supply wells. The integrated analysis was completed as part of the characterization of a fractured-sandstone aquifer in the mountainous setting of the Santa Susana Field Laboratory in southern Ventura County, California. In the deepest well, which was 1,768 feet deep and had the highest specific capacity (120 gallons per minute per foot), flow zones were detected at 380 feet (base of casing) and at 440, 595, and 770 feet in the open hole. Under ambient conditions, measured flow was downward from the 380- and 440-foot zones to the 595- and 770-foot zones. Under pumped conditions, most of flow was contributed by the 595-foot zone. Flow from the 380- and 440-foot zones appeared to have lower specific conductance and higher trichloroethylene concentrations than that from the 595-foot zone. In the shallowest well, which was reportedly 940 feet deep but only logged to 915 feet due to blockage, flow zones were detected behind the perforated casing and at 867 feet in the open hole. Under ambient conditions, downward and upward flows appeared to exit at a zone behind the perforated casing at 708 feet. Most of the pumped flow was contributed from zones behind the perforated casing between 565 and 708 feet. Pumped flow also was contributed by zones at 867 feet and below the logged depth. Volatile organic compounds were not detected in the ambient and pumped flows. In the third well, which was 1,272 feet deep and had the lowest specific capacity (3.6 gallons per minute per foot), flow zones were detected in the open hole above and just below the water level near 337 feet and at 615, 785, 995, and 1,070 feet. Under ambient conditions, measured flow in well was downward from the shallowmost zones to the 995-foot zone. Fracture zones at 615, 785, and 995 feet each contributed about one-third of the pumped flow measured below the pump. Volatile organic compounds were not detected in the ambient and pumped flows.

California↗
USGS2012

Structures data collection for the national map using volunteered geographic information

The U.S. Geological Survey (USGS) has historically sponsored volunteered data collection projects to enhance its topographic paper and digital map products. This report describes one phase of an ongoing project to encourage volunteers to contribute data to The National Map using online editing tools. The USGS recruited students studying geographic information systems (GIS) at the University of Colorado Denver and the University of Denver in the spring of 2011 to add data on structures - manmade features such as schools, hospitals, and libraries - to four quadrangles covering metropolitan Denver. The USGS customized a version of the online Potlatch editor created by the OpenStreetMap project and populated it with 30 structure types drawn from the Geographic Names Information System (GNIS), a USGS database of geographic features. The students corrected the location and attributes of these points and added information on structures that were missing. There were two rounds of quality control. Student volunteers reviewed each point, and an in-house review of each point by the USGS followed. Nine-hundred and thirty-eight structure points were initially downloaded from the USGS database. Editing and quality control resulted in 1,214 structure points that were subsequently added to The National Map . A post-project analysis of the data shows that after student edit and peer review, 92 percent of the points contributed by volunteers met National Map Accuracy Standards for horizontal accuracy. Lessons from this project will be applied to later phases. These include: simplifying editing tasks and the user interfaces, stressing to volunteers the importance of adding structures that are missing, and emphasizing the importance of conforming to editorial guidelines for formatting names and addresses of structures. The next phase of the project will encompass the entire State of Colorado and will allow any citizen to contribute structures data. Volunteers will benefit from this project by engaging with their local geography and contributing to a national resource of topographic information that remains in the public domain for anyone to download.

Denver↗
USGS2017

Determining the sources of fine-grained sediment using the Sediment Source Assessment Tool (Sed_SAT)

A sound understanding of sources contributing to instream sediment flux in a watershed is important when developing total maximum daily load (TMDL) management strategies designed to reduce suspended sediment in streams. Sediment fingerprinting and sediment budget approaches are two techniques that, when used jointly, can qualify and quantify the major sources of sediment in a given watershed. The sediment fingerprinting approach uses trace element concentrations from samples in known potential source areas to determine a clear signature of each potential source. A mixing model is then used to determine the relative source contribution to the target suspended sediment samples. The computational steps required to apportion sediment for each target sample are quite involved and time intensive, a problem the Sediment Source Assessment Tool (Sed_SAT) addresses. Sed_SAT is a user-friendly statistical model that guides the user through the necessary steps in order to quantify the relative contributions of sediment sources in a given watershed. The model is written using the statistical software R (R Core Team, 2016b) and utilizes Microsoft Access® as a user interface but requires no prior knowledge of R or Microsoft Access® to successfully run the model successfully. Sed_SAT identifies outliers, corrects for differences in size and organic content in the source samples relative to the target samples, evaluates the conservative behavior of tracers used in fingerprinting by applying a “Bracket Test,” identifies tracers with the highest discriminatory power, and provides robust error analysis through a Monte Carlo simulation following the mixing model. Quantifying sediment source contributions using the sediment fingerprinting approach provides local, State, and Federal land management agencies with important information needed to implement effective strategies to reduce sediment. Sed_SAT is designed to assist these agencies in applying the sediment fingerprinting approach to quantify sediment sources in the sediment TMDL framework.

Open-File Report↗
USGS2024

Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary

Executive Summary The Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of Reclamation to provide scientific support for the management of Reclamation’s CVP project. Major habitat restoration efforts and a new water-diversion point are planned to benefit delta smelt ( Hypomesus transpacificus ) and other species of concern while ensuring the reliability of water supply. In addition, various flow actions and management activities have been identified as possible methods to increase populations of delta smelt and salmonid ( Oncorhynchus spp.) runs of concern. The overarching goal of this cooperative project was to provide Reclamation with the scientific information needed to evaluate the efficacy of ongoing and future adaptive management actions and to improve the scientific basis for more flexible CVP operations that would achieve water-supply reliability and fish protection. The research and monitoring described in this report comprises the period 2015–19 and focuses on management issues related to native fish species of concern, especially delta smelt. Conserving the delta smelt population while providing a reliable water supply is a primary management and policy issue in California. Our approach for this cooperative project is based on the “physics to fish” concept, the idea that high-quality habitat is generated and sustained by the interaction between physical processes and the landscape. These interactions create a template for chemical and biological processes that can change across a variety of spatial and temporal scales. Following this concept, this project (hereafter referred to as “the physics to fish project”) included monitoring and studies of water flows, sediments, water quality, and invertebrate and fish dynamics across a range of spatial and temporal scales and in regions relevant to resource managers tasked with managing water supplies and ecosystem health in the San Francisco Estuary. The intent of this approach was to document the habitat conditions, important processes, and interactions among them that create high-quality habitat for native fishes so that the likely effects of future management actions (for example, habitat restoration) can be objectively assessed at the local (site-specific), regional (within subregions of the estuary), and landscape (across the entire estuary and beyond) scales. Hydrodynamically, the upper estuary (landward of Carquinez Strait) is characterized by a fixed volume of tidally exchanged water (for example, tidal prism) that interacts with the existing channel network and bathymetry to create regions with differing hydrodynamics. Our results indicate that careful study of construction or reoperation of existing infrastructure to perform management actions can help (1) improve the accuracy of hydrodynamic models; (2) further understanding of ecological effects; and (3) enhance abilities to predict ecological outcomes. At the local scale, we developed a new concept called the Lagrangian to Eulerian (LE) ratio that can be used as a tool for understanding the importance of various hydrodynamic processes in specific channels or channel networks and for forecasting transport dynamics. Channels with LE ratios<1 in a channel network or in a dead-end slough are hydrodynamically able to develop an exchange zone between two parcels of water that may have different chemical and physical properties. In a dead-end channel, there is a landward region with long residence time (no-exchange zone) and a seaward region with short residence time (high-exchange zone) that are well mixed with seaward waters. At the transition (exchange zone) between the high and no-exchange regions, a gradient will form in water-quality constituents that differ in concentration between the landward and seaward waters. Turbidity affects fish habitat and has declined through time in the San Francisco Estuary. Average turbidity across the Sacramento–San Joaquin Delta (hereafter referred to as “the Delta”) is dependent on annual hydrology. In dry years, the region around Cache Slough (known regionally as the “Cache Slough Complex”) in the northern Delta is generally more turbid than Suisun Bay and the lower Sacramento River. When the Yolo By-Pass (known regionally as “Yolo Bypass”), a large flood bypass that runs parallel to the Sacramento River in the northern Delta, is not flooding and river flows are lower, sediment is usually transported into the Cache Slough Complex because flood tides dominate ebb tides, resulting in transport of suspended sediment from seaward areas of the upper estuary into the Cache Slough Complex. These hydrodynamic conditions also favor the formation of turbidity maximums (TMs) in the Cache Slough Complex. The TMs are areas of higher suspended-sediment concentration, providing higher-turbidity habitat favored by some fishes, including delta smelt, and they can also concentrate other constituents, including phytoplankton and organic carbon that can be important in food webs. Pelagic primary production by phytoplankton is the basis for Delta food webs supporting pelagic fishes such as delta smelt; however, phytoplankton abundance in the Delta has declined during recent decades. We examined how nutrients, hydrodynamics, and other factors affect phytoplankton blooms. Based on our results, we developed three new concepts of phytoplankton bloom formation in the Delta, each associated with a distinct set of hydrologic conditions. First, productivity cascades highlighted how local processes can contribute to phytoplankton blooms observed at the regional scale. Second, we observed phytoplankton blooms in the upper San Francisco Estuary that were associated with transport out of Yolo By-Pass (transport blooms). Third, we also documented a series of phytoplankton blooms that were in the confluence area at the landward edge of Suisun Bay. The conditions leading to creation of confluence phytoplankton blooms are not yet understood, but the confluence region connects the Cache Slough Complex with Suisun Marsh. Therefore, blooms in this area have the potential to spread to large areas of the Delta. At the landscape scale, the distribution of the invasive clams ( Potamocorbula amurensis and Corbicula fluminea , hereafter referred to as “ Corbicula ”) is driven by salinity. At smaller spatial scales, the distribution of either species is sensitive to multiple factors affecting survival and reproduction, complicating efforts to predict distribution and abundance without considering local-scale conditions across the area of interest. In the Cache Slough Complex, the area landward of the exchange zone in regions with LE ratio<1 were characterized by low abundances of Corbicula probably because recruits from seaward areas are not transported past the exchange zone and because there are no landward tributaries with adult Corbicula to provide an upstream source of recruits. Corbicula biomass was highest near or downstream from the exchange zone consistent with Corbicula grazing on phytoplankton produced in the exchange zone or transported from the no-exchange zone. The severity of Corbicula grazing could be reduced by manipulating the hydrodynamic characteristics of waterways; however, the beneficial and harmful effects on the organisms meant to benefit from increased phytoplankton production, including zooplankton and fish species of concern, should be thoroughly examined before manipulating hydrodynamic characteristics. The distribution of fishes at the landscape scale is generally driven by the position of the salinity field in the estuary. The physics to fish project compared distributions of fishes at Ryer Island, a tidal wetland in Suisun Bay and a region of variable salinity, with fish distributions at the Cache Slough Complex, a freshwater region. At Ryer Island, there was an absence of freshwater invasive species and an abundance of native species, such as Sacramento splittail ( Pogonichthys macrolepidotus ), tule perch ( Hysterocarpus traskii ), and Sacramento pikeminnow ( Ptychocheilus grandis ). The native species were almost exclusively captured in wetland and nearshore shallow-water habitat regardless of water-quality conditions. In the Cache Slough Complex, our regional scale objective was to elucidate how hydrodynamic-physical habitat interactions drive fish-community structure. Our studies showed that dendritic channel systems were better able to support native species, while intertidal habitats supported those species best able to exploit the transient character of the habitat. Habitats upstream from the exchange zone were especially important in supporting high numbers of native fishes relative to within or downstream from the exchange zone. Many of the native species were associated with tidal marsh in the no-exchange zone. More pelagic-oriented, mobile species, such as Striped Bass ( Morone saxatilis ), threadfin shad ( Dorosoma petenense ), and Sacramento pikeminnow, were more affected by water-quality conditions, such as turbidity. The physics to fish concept developed in this project provides a framework for designing individual projects and for considering the cumulative effects of multiple projects in a region, using the LE ratio as a guiding metric. The physics to fish concept may also provide a suitable framework for coordinating management actions. Tidal wetlands can function in several ways in the hydrodynamic framework. Relatively small tidal wetlands with short channel networks and with LE ratios>1 are not able to maintain a landward no-exchange zone or an exchange zone. This likely means that any contributions to pelagic food webs would be limited to resources derived from wetland vegetation, which can include dissolved and particulate organic matter (detritus) and populations of consumers that can increase in abundance based on those resources. The fate of the contributed production from these channels depends on the characteristics of the receiving waters seaward of the tidal wetland. If these channels join a large system such as Suisun Bay, then any contribution is likely to be rapidly dispersed in the larger volume; however, the channel junction might provide a focal point for consumers, such as fishes, to congregate and feed on material leaving the wetland on ebb tides before it is dispersed in the larger volume. Fishes might also access these resources by entering the wetland. The physics to fish project has established a foundation and several new concepts for understanding how habitat restoration can benefit native fish populations at the local and regional levels. Many of the ideas regarding habitat restoration and channel modifications outlined in this report could help guide management actions that could improve conditions for native fishes at little or no water cost beyond water already dedicated to other management actions. A complete list of products originating from this work is provided in appendix 1.

California↗
USGS2012

Atmospheric inputs to watersheds of the Luquillo Mountains in eastern Puerto Rico: Chapter D in Water quality and landscape processes of four watersheds in eastern Puerto Rico

Twenty years of precipitation-chemistry data from the National Atmospheric Deposition Program site at El Verde, Puerto Rico, demonstrate that three major sources control the composition of solutes in rain in eastern Puerto Rico. In order of importance, these sources are marine salts, temperate contamination from the Northern Hemisphere, and Sahara Desert dust. Marine salts are a source of roughly 82 percent of the ionic charge in precipitation; marine salt inputs are greatest in January. Evaluation of 15 years of U.S. Geological Survey data for four watersheds in eastern Puerto Rico suggests that large storms, including hurricanes, are associated with exceptionally high chloride concentrations in stream waters. Some of these storms were missed in sampling by the National Atmospheric Deposition Program, and therefore its data on the marine contribution likely underestimate chloride. The marine contribution is a weak source of acidity. Temperate contamination contributes about 10 percent of the ionic charge in precipitation; contaminants are primarily nitrate, ammonia, and sulfate derived from various manmade and natural sources. Peak deposition of temperate contaminants is during January, April, and May, months in which strong weather fronts arrive from the north. Temperate contamination, a strong source of acidity, is the only component that is increasing through time. Sahara Desert dust provides 5 percent of the ionic charge in precipitation; it is strongly seasonal, peaking in June and July during times of maximum dust transport from the Sahara and sub-Saharan regions. This dust contributes, on average, enough alkalinity to neutralize the acidity in June and July rains.

Professional Paper↗
USGS2013

Peak streamflows and runoff volumes for the Central United States, February through September, 2011

During 2011, excessive precipitation resulted in widespread flooding in the Central United States with 33 fatalities and approximately $4.2 billion in damages reported in the Souris/Red River of the North (Souris/Red) and Mississippi River Basins. At different times, beginning in late February 2011 and extending through September 2011, various rivers in these basins had major flooding, with some locations receiving multiple rounds of flooding. Peak streamflow records were broken at 105 streamgages in the Souris/Red and Mississippi River Basins and annual runoff volume records set at 47 of the 211 streamgages analyzed for annual runoff. For the period of 1950 through 2011, the Ohio River provided almost one-half of the annual runoff at Vicksburg; the Missouri River contributed less than one-fourth, and the lower Mississippi River less than one-fourth. Those relative contribution patterns also occurred in 1973 and 2011, with the notable exception of the decrease in contribution of the lower Mississippi River tributaries and the increase in contribution from the upper Missouri River Basin in 2011 as compared to 1973 and the long-term average from 1950 to 2011.

Professional Paper↗
USGS2005

Estimated water use and availability in the South Coastal Drainage Basin, southern Rhode Island, 1995-99

The South Coastal Drainage Basin includes approximately 59.14 square miles in southern Rhode Island. The basin was divided into three subbasins to assess the water use and availability: the Saugatucket, Point Judith Pond, and the Southwestern Coastal Drainage subbasins. Because there is limited information on the ground-water system in this basin, the water use and availability evaluations for these subbasins were derived from delineated surface-water drainage areas. An assessment was completed to estimate water withdrawals, use, and return flow over a 5-year study period from 1995 through 1999 in the basin. During the study period, one major water supplier in the basin withdrew an average of 0.389 million gallons per day from the sand and gravel deposits. Most of the potable water is imported (about 2.152 million gallons per day) from the adjacent Pawcatuck Basin to the northwest. The estimated water withdrawals from the minor water suppliers, which are all in Charlestown, during the study period were 0.064 million gallons per day. The self-supplied domestic, industrial, commercial, and agricultural withdrawals from the basin were 0.574 million gallons per day. Water use in the basin was 2.874 million gallons per day. The average return flow in the basin was 1.190 million gallons per day, which was entirely from self-disposed water users. In this basin, wastewater from service collection areas was exported (about 1.139 million gallons per day) to the Narragansett Bay Drainage Basin for treatment and discharge. During times of little to no recharge, in the form of precipitation, the surface- and ground-water system flows are from storage primarily in the stratified sand and gravel deposits, although there is flow moving through the till deposits at a slower rate. The ground water discharging to the streams, during times of little to no precipitation, is referred to as base flow. The PART program, a computerized hydrograph-separation application, was used at the selected index stream-gaging station to determine water availability based on the 75th, 50th, and 25th percentiles of the total base flow, the base flow minus the 7-day, 10-year flow criteria, and the base flow minus the Aquatic Base Flow criteria at the index station. The base flow calculated at the selected index station was subdivided into two rates on the basis of the percent contributions from sandand-gravel and till deposits. There has been no long-term collection of surface-water data in this study area and therefore an index stream-gaging station in the Pawcatuck Basin was used for the South Coastal Drainage Basin. The Pawcatuck River at Wood River Junction was chosen as the index station for the South Coastal Drainage Basin because the station is representative of the basin on the basis of the percentage of sand and gravel deposits and the average extent of thickness of the sand and gravel deposits. The baseflow contributions from sand and gravel deposits at the index station were computed for June, July, August, and September, and applied to the percentage of surficial deposits at the index station. The base-flow contributions were converted to a per unit area at the station for the till, and for the sand and gravel deposits and applied to the South Coastal Drainage Basin to determine the water availability. The results from the index station, the Pawcatuck River at Wood River Junction streamgaging station, were lowest for the summer in September. To determine water availability in the South Coastal Drainage Basin, the per unit area of the estimated base flows from sand and gravel deposits and till deposits at the index station was applied to the subbasin areas, and the resultant flows were lowest in September. The base flow at the 75th percentile in the basin was 56.95 million gallons per day in June; 32.78 million gallons per day in July; 30.22 million gallons per day in August; and 23.94 million gallons per day in September. The base flow at the 50th percentile in the basin was 44.59 million gallons per day in June; 25.31 million gallons per day in July; 20.75 million gallons per day in August; and 17.01 million gallons per day in September. The base flow at the 25th percentile in the basin was 35.52 million gallons per day in June; 20.40 million gallons per day in July; 14.94 million gallons per day in August; and 12.00 million gallons per day in September. There are some limitations in the application of this method along the coast, because saltwater intrusion can change the amount of fresh ground-water discharge to the coastal saltwater ecosystem. A ground-water system analysis evaluating these variances would provide additional information to assess the water availability along the coast. Because water withdrawals and use are greater during the summer than other times of the year, water availability in June, July, August, and September was assessed and compared to water withdrawals in the basin. The ratios were calculated by dividing the water withdrawals by the water-availability flow scenarios at the 75th, 50th, and 25th percentiles for the basin, which are based on total water available from base-flow contributions from till and sand and gravel deposits in the basin. The closer the ratio is to one, the closer the withdrawals are to the estimated water available, and the net water available decreases. For the study period, the withdrawals in July were higher than the other summer months. The ratios in the basin for the base-flow scenario, with no low-flow criteria removed, ranged from 0.029 to 0.046 in June; 0.059 to 0.094 in July; 0.050 to 0.100 in August; and 0.040 to 0.079 in September. A long-term hydrologic budget (60 years) was calculated for the South Coastal Drainage Basin to identify and assess the basin and subbasin inflow and outflows. This coastal basin is different than other study areas because all three of the subbasins drain into salt water, Point Judith Point, Long Island Sound, and Rhode Island Sound towards the Atlantic Ocean, or internally within the subbasin to the salt ponds. The hydrologic budgets, therefore, were compiled by subbasin. The basin hydrologic budget is the sum of the three subbasin budgets. Unlike a river subbasin drainage system, however, the estimated streamflows out of the subbasins were also considered outflows from the basin. The water withdrawals and return flows used in the budget were from 1995 through 1999. For the hydrologic budget, it was assumed that inflow equals outflow, where the estimated inflows were from precipitation and wastewater-return flow, and the estimated outflows were from evapotranspiration, streamflow, and water withdrawals.

Rhode Island↗
USGS2006

Concentrations, and estimated loads and yields of nutrients and suspended sediment in the Little River basin, Kentucky, 2003-04

Nutrients, primarily nitrogen and phosphorus compounds, naturally occur but also are applied to land in the form of commercial fertilizers and livestock waste to enhance plant growth. Concentrations, estimated loads and yields, and sources of nitrite plus nitrate, total phosphorus, and orthophosphate were evaluated in streams of the Little River Basin to assist the Commonwealth of Kentucky in developing 'total maximum daily loads' (TMDLs) for streams in the basin. The Little River Basin encompasses about 600 square miles in Christian and Trigg Counties, and a portion of Caldwell County in western Kentucky. Water samples were collected in streams in the Little River Basin during 2003-04 as part of a study conducted in cooperation with the Kentucky Department of Agriculture. A total of 92 water samples were collected at four fixed-network sites from March through November 2003 and from February through November 2004. An additional 20 samples were collected at five synoptic-network sites during the same period. Median concentrations of nitrogen, phosphorus, and suspended sediment varied spatially and seasonally. Concentrations of nitrogen were higher in the spring (March-May) after fertilizer application and runoff. The highest concentration of nitrite plus nitrate-5.7 milligrams per liter (mg/L)-was detected at the South Fork Little River site. The Sinking Fork near Cadiz site had the highest median concentration of nitrite plus nitrate (4.6 mg/L). The North Fork Little River site and the Little River near Cadiz site had higher concentrations of orthophosphate in the fall and lower concentrations in the spring. Concentrations of orthophosphate remained high during the summer (June-August) at the North Fork Little River site possibly because of the contribution of wastewater effluent to streamflow. Fifty-eight percent of the concentrations of total phosphorus at the nine sites exceeded the U.S. Environmental Protection Agency recommended maximum concentration limit of 0.1 mg/L. Concentrations of suspended sediment were highest in the spring during runoff and lowest in the fall. The highest concentration of suspended sediment (1,020 mg/L) was observed at the Sinking Fork near Cadiz site. The median concentration of suspended sediment for all sites sampled was 12 mg/L. A nonparameteric statistical test (Wilcoxson rank-sum) showed that the median concentrations of suspended sediment were not different among any of the fixed-network sites. The Little River near Cadiz site contributed larger estimated mean annual loads of nitrite plus nitrate (2,500,000 pounds per year (lb/yr)) and total phosphorus (160,000 lb/yr) than the other three fixed-network sites. Of the two main upstream tributaries from the Little River near Cadiz site, the North Fork Little River was the greatest contributor of total phosphorus to the study area with an estimated mean annual load of 107,000 lb/yr or about 64 percent of the total estimated mean annual load at the Little River near Cadiz site. The other main upstream tributary, South Fork Little River, had an estimated mean annual load of total phosphorus that was about 20 percent of the mean annual load at the Little River near Cadiz site. Estimated loads of suspended sediment were largest at the Little River near Cadiz site, where the estimated mean annual load for 2003-04 was about 84,000,000 lb/yr. The North Fork Little River contributed an estimated 36 percent of the mean annual load of suspended sediment at the Little River near Cadiz site, while the South Fork Little River contributed an estimated 18 percent of the mean annual load at the Little River near Cadiz site. The North Fork Little River site had the largest estimated mean annual yield of total phosphorus (1,600 pounds per year per square mile (lb/yr/mi2)) and orthophosphate (1,100 lb/yr/mi2). A principal source of phosphorus for the North Fork Little River is discharge from wastewater-treatment facilities. The largest estimated mean annual yield of nitrite plus nitrate was observed at the South Fork Little River site. The North Fork Little River site had the largest estimated mean annual yield of suspended sediment (450,000 lb/yr/mi2). Inputs of nitrogen and phosphorus to streams from point and nonpoint sources were estimated for the Little River Basin. Commercial fertilizer and livestock-waste applications on row crops are a principal source of nutrients for most of the Little River Basin. Sources of nutrients in the urban areas of the basin mainly are from effluent discharge from wastewater-treatment facilities and fertilizer applications to lawns and golf courses.

Scientific Investigations Report↗
USGS2007

Influence of Locally Derived Recharge on the Water Quality and Temperature of Springs in Hot Springs National Park, Arkansas

The hot springs of Hot Springs National Park consist of a mixture of water from two recharge components: a primary hot-water component and a secondary cold-water component. Widespread distribution of fractures enables mixing of the hot- and cold-water components of flow near the discharge area for the springs. Urbanization in the area near the hot springs of Hot Springs National Park has increased the potential for degradation of the quality of surface-water runoff and locally derived ground-water recharge to the hot springs. Previous studies by the U.S. Geological Survey have indicated that water from some cold-water springs and wells in the vicinity of Hot Springs, Arkansas, showed evidence of contamination and that water from locally derived cold-water recharge might contribute 25 percent of the total flow to the hot springs after storms. Water samples were collected during base-flow conditions at nine hot springs and two cold-water springs in September 2000. Nine hot springs and one cold-water spring were resampled in October 2001 after a storm that resulted in a measurable decrease in water temperature in selected hot springs. Water samples were analyzed for a variety of dissolved chemical constituents (nutrients, major ions, trace elements, pesticides, semivolatile compounds, isotopes, and radiochemicals), physical properties, field measurements, and bacteria. Comparison of analyses of samples collected during base-flow conditions from the springs in 2000 and during a storm event in 2001 with the results from earlier studies dating back to the late 1800's indicates that little change in major, minor, and trace constituent chemistry has occurred and that the water continues to be of excellent quality. Water-quality data show distinguishable differences in water chemistry of the springs during base-flow and stormflow conditions, indicating changing input of cold-water recharge relative to hot-water recharge. Silica, total dissolved solids, strontium, barium, and sulfate show statistically significant differences between the median values of base-flow and stormflow samples. While variations in these constituents do not degrade water quality, the differences do provide evidence of variability in the factors controlling water quality of the hot springs and show that water quality is influenced by the locally derived, cold-water component of flow to the springs. Water temperature was measured continuously (3-minute intervals) between August 2000 and October 2002 at four hot springs. Continuous water-temperature data at the springs provide no indication of persistent long-term change in water temperature through time. Short time-scale water-temperature decreases occur in response to mixing of hot-springs water with locally derived recharge after storm events; the magnitude of these decreases varied inversely with the amount of rainfall. Maximum decreases in water temperature for specific storms had a non-linear relation with the amount of precipitation measured for the events. Response time for water temperature to begin decreasing from baseline temperature as a result of storm recharge was highly variable. Some springs began decreasing from baseline temperature as quickly as 1 hour after the beginning of a storm; one spring had an 8-hour minimum response time to show a storm-related temperature decrease. Water-quality, water-temperature, isotopic, and radiochemical data provide multiple lines of evidence supporting the importance of the contribution of cold-water recharge to hot springs. All the springs sampled indicated some measure of influence from local recharge. Binary mixing models using silica and total dissolved solids indicate that cold-water recharge from stormflow contributes an estimated 10 to 31 percent of the flow of hot springs. Models using water temperature indicate that cold-water recharge from stormflow contributes an estimated 1 to 35 percent of the flow of the various hot springs. Alth

Scientific Investigations Report↗
USGS2007

Estimation of Sediment Sources Using Selected Chemical Tracers in the Perry Lake and Lake Wabaunsee Basins, Northeast Kansas

In Kansas and nationally, stream and lake sediment is a primary concern as related to several important issues including water quality and reservoir water-storage capacity. The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. To investigate sources of sediment within the Perry Lake and Lake Wabaunsee Basins of northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediment were collected, analyzed, and compared. Subbasins sampled within the Perry Lake Basin included Atchison County Lake, Banner Creek Reservoir, Gregg Creek, Mission Lake, and Walnut Creek. The samples were sieved to isolate the less than 63-micron fraction (that is, the silt and clay) and analyzed for selected nutrients (total nitrogen and total phosphorus), organic and total carbon, 25 trace elements, and the radionuclide cesium-137 (137Cs). To determine which of the 30 constituents provided the best ability to discriminate between channel-bank and surface-soil sources in the two basins, four selection criteria were used. To be selected, it was required that the candidate constituent (1) was detectable, (2) had concentrations or activities that varied substantially and consistently between the sources, (3) had concentration or activity ranges that did not overlap between the sources, and (4) had concentration or activity differences between the sources that were statistically significant. On the basis of the four selection criteria, total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), and 137Cs were selected. Of the four selected constituents, 137Cs likely is the most reliable indicator of sediment source because it is known to be conservative in the environment. Trace elements were not selected because concentrations in the channel-bank and surface-soil sources generally were similar or did not vary in a consistent manner. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment prior to the sediment-source estimations, constituent ratio and clay-normalization techniques were used. Computed ratios included the ratio of TOC to TN, TOC to TP, and TN to TP. Constituent concentrations (TN, TP, TOC) and activities (137Cs) were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators (that is, three constituent ratios and the clay-normalized concentration or activity for four constituents). Sediment-source estimation for each reservoir was based on a comparison between the reservoir bottom sediment and the end member channel-bank and surface-soil sources. Within the Perry Lake Basin, the seven-indicator consensus indicated that both channel-bank and surface-soil sources were important contributors of the sediment deposited in Atchison County Lake and Banner Creek Reservoir, whereas channel-bank sources were the dominant source of sediment for Mission Lake. On the sole basis of 137Cs activity, surface-soil sources contributed the most sediment to Atchison County Lake, and channel-bank sources contributed the most sediment to Banner Creek Reservoir and Mission Lake. For Perry Lake, both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant and that channel-bank sources increased in importance with distance downstream in the Perry Lake Basin. For Lake Wabaunsee, the seven-indicator consensus and 137Cs indicated that both channel-bank and surface-soil sources were important. Given that the relative contribution of sediment from channel-bank and surface-soil sources can vary within and between basins and over time, basin-specific strategies for sediment management and monitoring are appropriate.

Scientific Investigations Report↗
USGS2008

Estimation of Constituent Concentrations, Loads, and Yields in Streams of Johnson County, Northeast Kansas, Using Continuous Water-Quality Monitoring and Regression Models, October 2002 through December 2006

Johnson County is one of the most rapidly developing counties in Kansas. Population growth and expanding urban land use affect the quality of county streams, which are important for human and environmental health, water supply, recreation, and aesthetic value. This report describes estimates of streamflow and constituent concentrations, loads, and yields in relation to watershed characteristics in five Johnson County streams using continuous in-stream sensor measurements. Specific conductance, pH, water temperature, turbidity, and dissolved oxygen were monitored in five watersheds from October 2002 through December 2006. These continuous data were used in conjunction with discrete water samples to develop regression models for continuously estimating concentrations of other constituents. Continuous regression-based concentrations were estimated for suspended sediment, total suspended solids, dissolved solids and selected major ions, nutrients (nitrogen and phosphorus species), and fecal-indicator bacteria. Continuous daily, monthly, seasonal, and annual loads were calculated from concentration estimates and streamflow. The data are used to describe differences in concentrations, loads, and yields and to explain these differences relative to watershed characteristics. Water quality at the five monitoring sites varied according to hydrologic conditions; contributing drainage area; land use (including degree of urbanization); relative contributions from point and nonpoint constituent sources; and human activity within each watershed. Dissolved oxygen (DO) concentrations were less than the Kansas aquatic-life-support criterion of 5.0 mg/L less than 10 percent of the time at all sites except Indian Creek, which had DO concentrations less than the criterion about 15 percent of the time. Concentrations of suspended sediment, chloride (winter only), indicator bacteria, and pesticides were substantially larger during periods of increased streamflow. Suspended-sediment concentration was nearly always largest at the Mill Creek site. The Mill Creek watershed is undergoing rapid development that likely contributed to larger sustained sediment concentrations. During most of the time, the smallest sediment concentrations occurred at the Indian Creek site, the most urban of the monitored sites, likely because most of the streamflow originates from wastewater-treatment facilities located just upstream from the monitoring site. However, estimated annual suspended-sediment load and yield were largest annually at the Indian Creek site because of substantial contributions during storm runoff. At least 90 percent of the total annual sediment load in 2005?06 at all five monitoring sites occurred in less than 2 percent of the time, generally associated with large storm runoff. About 50 percent of the 2005 sediment load at the Blue River site occurred during a single 3-day storm, the equivalent of less than 1 percent of the time. Suspended-sediment concentration is statistically related to other water-quality constituents, and these relations have potential implications for implementation of best management practices because, if sediment concentrations are decreased, concentrations of sediment-associated constituents such as suspended solids, some nutrients, and bacteria will also likely decrease. Chloride concentrations were largest at the Indian and Mill Creek sites, the two most urban stream sites which also are most affected by road-salt runoff and wastewater-treatment-facility discharges. Two chloride runoff occurrences in January?February 2005 accounted for 19 percent of the total chloride load in Indian Creek in 2005. Escherichia coli density at the Indian Creek site was nearly always largest of the five sites with a median density more than double that of any other site and 15 times the density at the Blue River site which is primarily nonurban. More than 97 percent of the fecal coliform bacteria load at the Indian Creek site and near the B

Scientific Investigations Report↗
USGS2009

Hydrology of the Johnson Creek Basin, Oregon

The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn and winter precipitation totals were used to anticipate flooding of Holgate Lake. Several factors affect annual mean flow of Johnson Creek. More precipitation falls in the southeastern area of the basin because of the topographic setting. Runoff from much of the northern and western areas of the basin does not flow into Johnson Creek due to permeable deposits, interception by combined sewer systems, and by groundwater flow away from Johnson Creek. Inflow from Crystal Springs Creek accounts for one-half of the increase in streamflow of Johnson Creek between the Sycamore and Milwaukie sites. Low flows of Johnson Creek vary as a result of fluctuations in groundwater discharge to the creek, although past water uses may have decreased flows. The groundwater contributions to streamflow upstream of river mile (RM) 5.5 are small compared to contributions downstream of this point. Comparison of flows to a nearby basin indicates that diversions of surface water may have resulted in a 50 percent decrease in low flows from about 1955 to 1977. Runoff from the drainage basin area upstream of the Johnson Creek at Sycamore site contributes more to peak streamflow and peak volume than the drainage basin area between the Sycamore and Milwaukie sites. The average increase in annual peak streamflow and annual peak volume between the two sites was 11 and 24 percent, respectively. Decreased contribution in the lower area of the drainage basin is a result of infiltration, interception by drywell and combined sewer systems, and temporary overbank storage. Trends in flow typically associated with increasing urban development were absent in Johnson Creek. Annual, low, and high flows showed no trend from 1941 to 2006. Much of the infrastructure that may affect runoff from agricultural, residential, and urban development was in place prior to collection of hydrologic data in the basin. Management of stormwater in the urban areas by routing runoff from impervious surfaces to dry

Oregon↗
USGS2010

Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer pumping on the Upper Floridan aquifer at Hunter Army Airfield, Chatham County, Georgia

Test drilling and field investigations, conducted at Hunter Army Airfield (HAAF), Chatham County, Georgia, during 2009, were used to determine the geologic, hydraulic, and water-quality characteristics of the Floridan aquifer system and to evaluate the effect of Lower Floridan aquifer (LFA) pumping on the Upper Floridan aquifer (UFA). Field investigation activities included (1) constructing a 1,168-foot (ft) test boring and well completed in the LFA, (2) collecting drill cuttings and borehole geophysical logs, (3) collecting core samples for analysis of vertical hydraulic conductivity and porosity, (4) conducting flowmeter and packer tests in the open borehole within the UFA and LFA, (5) collecting depth-integrated water samples to assess basic ionic chemistry of various water-bearing zones, and (6) conducting aquifer tests in the new LFA well and in an existing UFA well to determine hydraulic properties and assess interaquifer leakage. Using data collected at the site and in nearby areas, model simulation was used to quantify the effects of interaquifer leakage on the UFA and to determine the amount of pumping reduction required in the UFA to offset drawdown resulting from the leakage. Borehole-geophysical and flowmeter data indicate the LFA at HAAF consists of limestone and dolomitic limestone between depths of 703 and 1,080 ft, producing water from six major permeable zones: 723-731; 768-785; 818-837; 917-923; 1,027-1,052; and 1,060-1,080 ft. Data from a flowmeter survey, conducted at a pumping rate of 748 gallons per minute (gal/min), suggest that the two uppermost zones contributed 469 gal/min or 62.6 percent of the total flow during the test. The remaining four zones contributed from 1.7 to 18 percent of the total flow. Grab water samples indicate that with the exception of fluoride, constituent concentrations in the LFA increased with depth; water from the deepest interval (1,075 ft) contained chloride and sulfate concentrations of 480 and 240 milligrams per liter (mg/L), respectively. These relatively high concentrations were interpreted to have little effect on the overall quality of the well because flowmeter results indicated that water from 1,060 to 1,080 ft contributed less than 2 percent of the total flow to the completed well. Results of a 72-hour aquifer test indicate that pumping a LFA well at a rate of 748 gal/min produced a drawdown response of 0.76 ft in a well completed in the UFA located 176 ft from the pumped well. A revised regional groundwater-flow model was used to simulate long-term (steady-state) leakage response of the UFA to pumping from the LFA and to estimate the equivalent amount of pumping from the UFA that would produce similar drawdown. Pumping the well at a rate of 748 gal/min (about 1 million gallons per day [Mgal/d]) resulted in a maximum simulated steady-state drawdown of 36.2 ft in the LFA and was greater than 1 ft over a 146 square-mile area. Simulated steady-state drawdown in the overlying UFA that resulted from interaquifer leakage was greater than 1 ft over a 141 square-mile area and was 2.03 ft at the pumped well. Flow to the pumped well was derived from increased lateral flow across the specified-head boundary (0.02 Mgal/d) and increased leakage from the UFA (0.52 Mgal/d), and by reductions in discharge to the Lower Floridan confining unit (0.53 Mgal/d) and to the lateral specified-head boundary (0.53 Mgal/d). Sixty-five percent of the leakage from the UFA occurred within 1 mile of the pumped well. This larger contribution results from a larger head gradient between the pumped well and the overlying aquifer in areas close to the pumped well. The Georgia Environmental Protection Division interim permitting strategy for the LFA requires simulation of (1) aquifer leakage from the UFA to LFA resulting from pumping the new LFA well, and (2) the equivalent rate of UFA pumping that induces the identical maximum drawdown in the UFA that would be expected as a result of pumping th

Georgia↗
USGS2010

Nitrate-N movement in groundwater from the land application of treated municipal wastewater and other sources in the Wakulla Springs springshed, Leon and Wakulla Counties, Florida, 1966-2018

The City of Tallahassee began a pilot study in 1966 at the Southwest Farm sprayfield to determine whether disposal of treated municipal wastewater using center pivot irrigation techniques to uptake nitrate-nitrogen (nitrate-N) is feasible. Based on the early success of this project, a new, larger Southeast Farm sprayfield was opened in November 1980. However, a recent 2002 study indicated that nitrate-N from these operations may be moving through the Upper Floridan aquifer to Wakulla Springs, thus causing nitrate-N concentrations to increase in the spring water. The increase in nitrate-N combined with the generally clear spring water and abundant sunshine may be encouraging invasive plant species growth. Determining the link between the nitrate-N application at the sprayfields and increased nitrate-N levels is complicated because there are other sources of nitrate-N in the Wakulla Springs springshed, including atmospheric deposition, onsite sewage disposal systems, disposal of biosolids by land spreading, creeks discharging into sinks, domestic fertilizer application, and livestock wastes. Groundwater flow and fate and transport modeling were conducted to simulate the effect of all of the nitrate-N sources on Wakulla Springs from January 1, 1966, through December 31, 2018. The total simulated nitrate-N load to Wakulla Springs in 1967 was a relatively modest 69,000 kilograms per year (kg/yr). The major sources of the nitrate-N load in 1967 were determined to be: 1. Inflow to the study area across the lateral model boundaries at 31,000 kg/yr (45 percent), 2. Biosolids disposal by land spreading at 14,000 kg/yr (20 percent), 3. Creeks discharging into sinks at 7,800 kg/yr (11 percent), and 4. The Southwest Farm sprayfield at 4,500 kg/yr (7 percent). The total simulated nitrate-N load to Wakulla Springs in 1987 had increased dramatically to 297,000 kg/yr. The major sources of nitrate-N load in 1987 were determined to be: 1. The Southeast Farm sprayfield at 186,000 kg/yr (63 percent), 2. Biosolids at 37,000 kg/yr (12 percent), and 3. Inflow to the study area across the lateral model boundaries at 36,000 at kg/yr (12 percent). All of the other sources were 5 percent or less. The Wakulla Springs discharge can change rapidly, even during periods of little or no rainfall. This rapid change is probably the result of Wakulla Springs intermittently capturing groundwater that has been going to the Spring Creek Springs Group. This spring group is located in a marine estuary and is affected by tidally influenced saltwater intrusion. Two modeling scenarios were simulated and results are presented for 2007 and 2018 in an effort to bracket the range of possible current and future changes in the flow of Wakulla Springs. In scenario 1, it was assumed that Wakulla Springs was not capturing Spring Creek Springs Group flow. In scenario 2, it was assumed that Wakulla Springs was capturing Spring Creek Springs Group flow. Under the assumptions of scenario 1, the total simulated nitrate-N load to Wakulla Springs in 2007 was 207,200 kg/yr. The major sources of nitrate-N load were determined to be: 1. The Southeast Farm sprayfield at 111,000 kg/yr 53 percent), 2. Inflow to the study area across the lateral model boundaries at 44,000 at kg/yr (21 percent), and 3. Onsite sewage disposal systems at 24,000 kg/yr (12 percent). All of the other sources contributed 6 percent or less. Under the assumptions of scenario 2, the total simulated nitrate-N load to Wakulla Springs was 294,000 kg/yr. The major sources of nitrate-N load were determined to be: 1. The Southeast Farm sprayfield at 111,000 kg/yr (38 percent), 2. Onsite sewage disposal systems at 56,000 kg/yr (19 percent), 3. Inflow to the study area across the lateral model boundaries at 52,000 at kg/yr (18 percent), and 4. Creeks discharging into sinks at 31,000 kg/yr (11 percent). All of the other sources contributed 8 percent or less. The nitrate-N loads to Wakulla Springs from the Southeast Farm sprayfield for scenarios 1 and 2 were both 111,000 kg/yr. These amounts were the same because most of the water from the Southeast Farm sprayfield went into Wakulla Springs in both simulations. In contrast, the nitrate-N loads from onsite sewage disposal systems for scenarios 1 and 2 were 24,000 kg/yr and 56,000 kg/yr, respectively. The additional water captured by Wakulla Springs in scenario 2 came from an area that had a high density of residential and commercial sites using onsite sewage disposal systems Under the assumptions of scenario 1, the total simulated nitrate-N load to Wakulla Springs in 2018 will be 156,000 kg/yr. The major sources of nitrate-N load for scenario 1 are anticipated to be: 1. Inflow to the study area across the lateral model boundaries at 48,000 at kg/yr (31 percent), 2. The Southeast Farm sprayfield at 42,000 kg/yr (27 percent), 3. Onsite sewage disposal systems at 32,000 kg/yr (21 percent), and 4. Fertilizer at 17,000 kg/yr (11 percent). All of the other sources will contribute 5 percent or less. Under the assumptions of scenario 2, the total simulated nitrate-N load to Wakulla Springs in 2018 will be 266,000 kg/yr. The major sources of nitrate-N load for scenario 2 are anticipated to be: 1. Onsite sewage disposal systems at 80,000 kg/yr (30 percent), 2. Inflow to the study area across the lateral model boundaries at 57,000 at kg/yr (21 percent), 3. The Southeast Farm sprayfield at 43,000 kg/yr (16 percent), 4. Creeks discharging into sinks at 31,000 kg/yr (12 percent), and 5. Fertilizer at 32,000 kg/yr (12 percent). All of the other sources will contribute 6 percent or less. The simulated nitrate-N load from the Southeast Farm sprayfield to Wakulla Springs during 2007 through 2018 decreases from 111,000 kg/yr to 42,000 kg/yr in scenario 1 and decreases from 111,000 kg/yr to 43,000 kg/yr in scenario 2. Both scenarios show these decreases because of the simulated planned reduction in the concentration of nitrate-N in the wastewater used for irrigation from approximately 12 milligrams per liter (mg/L) in 2007 to 3 mg/L in 2018. In contrast, the simulated nitrate-N load from onsite sewage disposal systems to Wakulla Springs from 2007 through 2018 increases from 24,000 kg/yr to 32,000 kg/yr in scenario 1, and increases from 56,000 kg/yr to 80,000 kg/yr in scenario 2. Both scenarios show increases respective to the increases in population and residential and commercial sites using onsite sewage disposal systems. In addition, the simulated nitrate-N load to Wakulla Springs from 2007 through 2018 from inflow to the study area across the lateral model boundaries increases from 44,000 kg/yr to 48,000 kg/yr in scenario 1, and increases from 54,000 kg/yr to 57,000 kg/yr in scenario 2. Both scenarios show increases due to increasing nitrate-N levels upgradient in Leon County.

Scientific Investigations Report↗
USGS2010

Occurrence and sources of Escherichia coli in metropolitan St. Louis streams, October 2004 through September 2007

The occurrence and sources of Escherichia coli (E. coli) , one of several fecal indicator bacteria, in metropolitan St. Louis streams known to receive nonpoint source runoff, occasional discharges from combined and sanitary sewers, and treated wastewater effluent were investigated from October 2004 through September 2007. Three Missouri River sites, five Mississippi River sites, and six small basin tributary stream sites were sampled during base flow and storm events for the presence of E. coli and their sources. E. coli host-source determinations were conducted using local library based genotypic methods. Human fecal contamination in stream samples was additionally confirmed by the presence of Bacteroides thetaiotaomicron , an anaerobic, enteric bacterium with a high occurrence in, and specificity to, humans. Missouri River E. coli densities and loads during base flow were approximately 10 times greater than those in the Mississippi River above its confluence with the Missouri River. Although substantial amounts of E. coli originated from within the study area during base flow and storm events, considerable amounts of E. coli in the Missouri River, as well as in the middle Mississippi River sections downstream from its confluence with the Missouri River, originated in Missouri River reaches upstream from the study area. In lower Mississippi River reaches, bacteria contributions from the numerous combined and sanitary sewer overflows within the study area, as well as contributions from nonpoint source runoff, greatly increased instream E. coli densities. Although other urban factors cannot be discounted, average E. coli densities in streams were strongly correlated with the number of upstream combined and sanitary sewer overflow points, and the percentage of upstream impervious cover. Small basin sites with the greatest number of combined and sanitary sewer overflows (Maline Creek and the River des Peres) had larger E. coli densities, larger loads, and a greater percentage of E. coli attributable to humans than other small basin sites; however, even though small basin E. coli densities typically were much larger than in large river receiving streams, small basins contributed, on average, only a small part (a maximum of 16 percent) of the total E. coli load to larger rivers. On average, approximately one-third of E. coli in metropolitan St. Louis streams was identified as originating from humans. Another one-third of the E. coli was determined to have originated from unidentified sources; dogs and geese contributed lesser amounts, 10 and 20 percent, of the total instream bacteria. Sources of E. coli were largely independent of hydrologic conditions—an indication that sources remained relatively consistent with time.

Missouri↗
USGS2010

Effects of wastewater effluent discharge and treatment facility upgrades on environmental and biological conditions of the upper Blue River, Johnson County, Kansas and Jackson County, Missouri, January 2003 through March 2009

The Johnson County Blue River Main Wastewater Treatment Facility discharges into the upper Blue River near the border between Johnson County, Kansas and Jackson County, Missouri. During 2005 through 2007 the wastewater treatment facility underwent upgrades to increase capacity and include biological nutrient removal. The effects of wastewater effluent on environmental and biological conditions of the upper Blue River were assessed by comparing an upstream site to two sites located downstream from the wastewater treatment facility. Environmental conditions were evaluated using previously and newly collected discrete and continuous data, and were compared with an assessment of biological community composition and ecosystem function along the upstream-downstream gradient. This evaluation is useful for understanding the potential effects of wastewater effluent on water quality, biological community structure, and ecosystem function. In addition, this information can be used to help achieve National Pollution Discharge Elimination System (NPDES) wastewater effluent permit requirements after additional studies are conducted. The effects of wastewater effluent on the water-quality conditions of the upper Blue River were most evident during below-normal and normal streamflows (about 75 percent of the time), when wastewater effluent contributed more than 20 percent to total streamflow. The largest difference in water-quality conditions between the upstream and downstream sites was in nutrient concentrations. Total and inorganic nutrient concentrations at the downstream sites during below-normal and normal streamflows were 4 to 15 times larger than at the upstream site, even after upgrades to the wastewater treatment facility were completed. However, total nitrogen concentrations decreased in wastewater effluent and at the downstream site following wastewater treatment facility upgrades. Similar decreases in total phosphorus were not observed, likely because the biological phosphorus removal process was not optimized until after the study was completed. Total nitrogen and phosphorus from the wastewater treatment facility contributed a relatively small percentage (14 to 15 percent) to the annual nutrient load in the upper Blue River, but contributed substantially (as much as 75 percent) to monthly loads during seasonal low-flows in winter and summer. During 2007 and 2008, annual discharge from the wastewater treatment facility was about one-half maximum capacity, and estimated potential maximum annual loads were 1.6 to 2.4 times greater than annual loads before capacity upgrades. Even when target nutrient concentrations are met, annual nutrient loads will increase when the wastewater treatment facility is operated at full capacity. Regardless of changes in annual nutrient loads, the reduction of nutrient concentrations in the Blue River Main wastewater effluent will help prevent further degradation of the upper Blue River. The Blue River Main Wastewater Treatment Facility wastewater effluent caused changes in concentrations of several water-quality constituents that may affect biological community structure and function including larger concentrations of bioavailable nutrients (nitrate and orthophosphorus) and smaller turbidities. Streambed-sediment conditions were similar along the upstream-downstream gradient and measured constituents did not exceed probable effect concentrations. Habitat conditions declined along the upstream-downstream gradient, largely because of decreased canopy cover and riparian buffer width and increased riffle-substrate fouling. Algal biomass, primary production, and the abundance of nutrient-tolerant diatoms substantially increased downstream from the wastewater treatment facility. Likewise, the abundance of intolerant macroinvertebrate taxa and Kansas Department of Health and Environment aquatic-life-support scores, derived from macroinvertebrate data, significantly decreased downstream from the wastewater treatment facility. Ecosystem functional health, evaluated using a preliminary framework based on primary production and community respiration, downstream from the wastewater treatment facility was mildly impaired relative to the upstream site during summer 2008 but not during other times of the year. Upgrades to the Blue River Main Wastewater Treatment Facility improved wastewater effluent quality, but the wastewater effluent discharge still had negative effects on the water quality and biological conditions at the downstream sites. Wastewater effluent discharge into the upper Blue River likely contributed to changes in measures of ecosystem structure (streamflow, water chemistry, algal biomass, algal periphyton and macroinvertebrate community composition) and primary production, a measure of ecosystem function, along the upstream-downstream gradient. Because the Blue River Main Wastewater Treatment Facility is located in a rapidly urbanizing area, urbanization effects also may play a role in the decline in environmental and biological conditions along the upstream-downstream gradient. Despite these differences in environmental and biological conditions, ecosystem functional health was not impaired downstream from the WWTF during most times of the year, indicating the declines in environmental and biological conditions along the upstream-downstream gradient were not substantial enough to cause persistent changes in ecosystem function.

Kansas, Missouri↗
USGS2011

Simulation of the shallow groundwater-flow system near Mole Lake, Forest County, Wisconsin

The shallow groundwater system near Mole Lake, Forest County, Wis. was simulated using a previously calibrated regional model. The previous model was updated using newly collected water-level measurements and refinements to surface-water features. The updated model was then used to calculate the area contributing recharge for one existing and two proposed pumping locations on lands of the Sokaogon Chippewa Community. Delineated 1-, 5-, and 10-year areas contributing recharge for existing and proposed wells extend from the areas of pumping to the northeast of the pumping locations. Steady-state pumping was simulated for two scenarios: a base pumping scenario using pumping rates that reflect what the Tribe expects to pump and a high pumping scenario, in which the rate was set to the maximum expected from wells installed in this area. In the base pumping scenario, pumping rates of 32 gallons per minute (gal/min; 46,000 gallons per day (gal/d)) from the existing well and 30 gal/min (43,000 gal/d) at each of the two proposed wells were simulated. The high pumping scenario simulated a rate of 70 gal/min (101,000 gal/d) from each of the three pumping wells to estimate of the largest areas contributing recharge that might be expected given what is currently known about the shallow groundwater system. The areas contributing recharge for both the base and high pumping scenarios did not intersect any modeled surface-water bodies; however, the high pumping scenario had a larger areal extent than the base pumping scenario and intersected a septic separator.

Wisconsin↗
USGS2012

Groundwater quality and simulation of sources of water to wells in the Marsh Creek valley at the U.S. Geological Survey Northern Appalachian Research Laboratory, Tioga County, Pennsylvania

This report provides a November 2010 snapshot of groundwater quality and an analysis of the sources of water to wells at the U.S. Geological Survey (USGS) Northern Appalachian Research Laboratory (NARL) near Wellsboro, Pennsylvania. The laboratory, which conducts fisheries research, currently (2011) withdraws 1,000 gallons per minute of high-quality groundwater from three wells completed in the glacial sand and gravel aquifer beneath the Marsh Creek valley; a fourth well that taps the same aquifer provides the potable supply for the facility. The study was conducted to document the source areas and quality of the water supply for this Department of Interior facility, which is surrounded by the ongoing development of natural gas from the Marcellus Shale. Groundwater samples were collected from the four wells used by the NARL and from two nearby domestic-supply wells. The domestic-supply wells withdraw groundwater from bedrock of the Catskill Formation. Samples were analyzed for major ions, nutrients, trace metals, radiochemicals, dissolved gases, and stable isotopes of oxygen and hydrogen in water and carbon in dissolved carbonate to document groundwater quality. Organic constituents (other than hydrocarbon gases) associated with hydraulic fracturing and other human activities were not analyzed as part of this assessment. Results show low concentrations of all constituents. Only radon, which ranged from 980 to 1,310 picocuries per liter, was somewhat elevated. These findings are consistent with the pristine nature of the aquifer in the Marsh Creek valley, which is the reason the laboratory was sited at this location. The sources of water and areas contributing recharge to wells were identified by the use of a previously documented MODFLOW groundwater-flow model for the following conditions: (1) withdrawals of 1,000 to 3,000 gallons per minute from the NARL wells, (2) average or dry hydrologic conditions, and (3) withdrawals of 1,000 gallons per minute from a new well 3,500 feet to the southwest that was drilled to provide water for Marcellus gas-well operations. Results of simulations indicate that during average hydrologic conditions, infiltration from Straight Run, a tributary to Marsh Creek, provides nearly all the water to the NARL wells. During dry conditions, the areas contributing recharge expand such that Asaph Run contributes about half of the water to the NARL wells when withdrawals are 1,000 or 2,000 gallons per minute. The addition of a simulated withdrawal of 1,000 gallons per minute from the nearby new well does not substantially affect the sources of water captured by the NARL wells. These results are subject to some limitations. The water-quality samples represent a snapshot of groundwater chemistry for only one hydrologic condition; the concentrations of some constituents may change temporally. In addition, samples were collected and analyzed for hydrocarbon gases, but not organic constituents associated with hydraulic fracturing; additional sampling for these constituents would provide a more complete water-quality baseline. The sources contributing water to the NARL wells and the new well were simulated by use of a simplified one-layer model of the glacial sand and gravel aquifer for steady-state conditions that in reality are never achieved. Steady-state simulations of dry hydrologic conditions show that it is possible for the NARL wells to capture water from Asaph Run; however, maps of simulated groundwater time-of-travel indicate that a dry period of unusually long duration would be required. A better analysis could be done by recalibrating the groundwater-flow model with a finite-difference grid having multiple layers, cells smaller than the 200-foot by 200-foot cells used in this study, and transient stress periods.

Pennsylvania↗